In general, the present invention relates to a system and components for correcting spinal defects. More specifically, the present invention is directed to spinal fixation systems including spinal rods and spinal rod interconnecting assemblies to treat and correct spinal deformities.
Spinal fixation systems are implanted during a surgical procedure to treat a variety of problems. These treatments include correction of congenital spinal deformities, e.g., scoliosis, spondylolisthesis, kyphosis, lordosis, and arthropathy; repair of spinal injuries; and fusion of vertebrae to stabilize congenital conditions and/or alleviate chronic lower back pain. Several techniques and systems have been developed for correcting and stabilizing the spine and facilitating spinal fusion.
In one common system, a longitudinal member such as a bendable rod, or spinal rod, is disposed along the vertebral column and is fixed at selected points to various vertebra along the length of the column by any number of fixation elements. A variety of these vertebral fixation elements are known and include hooks and bone screws. These fixation elements are configured to engage and attach to specific portions of the vertebrae. Usually, the surgeon attaches a vertebral fixation element to the spine in an appropriate anatomical position and then attaches each vertebral fixation element to the spinal rod. In conjunction, the surgeon twists and/or realigns the spinal column and/or individual vertebra to provide the desired treatment for the spinal defect. Consequently, the spinal rods may be bent or orientated along the spinal column non-parallel to each other.
The spinal rods are typically connected together to provide a more rigid support and alignment system, much like a ladder with rungs running between the supports. The cross-connecting members should accommodate the different orientations of the spinal rods. Further, the connecting members should be able to bridge the gap between the spinal rods without interfering with the structures and nerves, e.g., the spinal cord and/or spinal processes associated with or adjacent to the spinal column. Additionally, the connecting member should rigidly and securely interconnect the spinal rods. Obviously, failure of the system and dislocation of the spinal rods and associated components can cause the patient great pain and require additional surgical procedures to correct. An adjustable yet rigid cross connector would facilitate treatment of spinal defects.
Any surgical operation, by nature, is a delicate procedure; operations proximate to the spinal column are even more delicate and demanding. In addition to the expected surgical procedures, the surgeon must force the spinal column and individual vertebra into alignment. During this procedure or immediately thereafter, the surgeon must position the fixation elements, assemble the spinal rod system, secure the spinal rod system to the vertebrae, and then tighten the connections in the entire system so no further movement occurs. Assembly of the spinal rod system can be very difficult, especially when the components are coated with body fluids. A more “user friendly” spinal fixation system that could be assembled quickly and reliably in the operating room would be a great benefit to both surgeons and their patients.
Thus, in light of the above-described problems, there is a continuing need for advancements in the relevant field, including improved spinal fixation assemblies, related components, and methods for treating spinal defects. The present invention is such an advancement and provides a wide variety of benefits and advantages.